Dr Oleg Brandt

Oleg Brandt is a Professor of Experimental Physics in the High Energy Physics group of the Cavendish Laboratory. Together with his team, he searches for dark matter, long-lived particles and other exciting new phenomena, at colliders like the Large Hadron Collider (LHC) of CERN and beyond.

Biography

Oleg studied at the Universities of Bonn and Amsterdam (2006) and received his PhD from University of Oxford (2009) for his work on prototyping searches for supersymmetry at the LHC and alignment and commissioning of the ATLAS tracker. Oleg then studied the properties of the top quark, resulting in the world’s most precise top quark mass measurement at that time, as a Fermi International Fellow at Fermilab and as a postdoctoral fellow at the University of Goettingen. From 2013, Oleg led a team of researchers at Heidelberg University funded through the federal Excellence Initiative, with the main focus on searches for Dark Matter at the LHC and new unexplored experimental signatures. In 2019, Oleg was appointed at the University of Cambridge, where he extended the scope of his research to include long-lived particle signatures, a vibrant and dynamically developing field due to unprecedented opportunities in LHC Run 3 and its high-luminosity upgrade. This line of Oleg’s research is generously funded through the UKRI Future Leaders Fellowship.

Beyond physics

Since 2020, Oleg chairs the IT Strategy Committee that oversees the delivery of IT services to the Department of Physics and the migration of IT services to the Ray Dolby Centre from an academic perspective. Until recently, Oleg represented HEP in the Strategy Working Group that is concerned with devising a coherent research vision for the Department.

Beyond academia

Oleg’s other passions include open water swimming, free diving, hiking, as well as science communication and education.

Research

Research mission

Fundamental laws of nature and fundamental particles broadly define the active research area of our team. Our overall research mission is the search for Dark Matter that comprises 85% of the matter in our universe. We are particularly interested in potential anomalies associated with the most recently discovered fundamental particle - the Higgs boson.

Research focus

The main research focus of our team is on potential Dark Sector particles with long lifetimes above 100 ps. For this, we use the ATLAS detector to analyse proton-proton collision data at the Large Hadron Collider (LHC) of CERN. The ATLAS detector has a very good sensitivity to such particles with lifetimes below about 10 ns. To probe lifetimes above 10 ns, we have recently proposed the ANUBIS detector that will complement the ATLAS detector. The Cambridge HEP group is leading the active exploration of the ANUBIS detector concept through detailed simulations and by measuring particle fluxes in-situ inside the ATLAS cavern starting 2022, i.e., in LHC Run 3.

In addition, our team is active in the area of searches for Dark Matter particles, where we are exploring exotic signatures that could not be covered efficiently previously. We are also active in R&D of particle detectors (and their operation), the key to study fundamental particles and their interactions, and to push the borders of the unknown at future colliders.

Research funding

The high impact of our research on long-lived particles is acknowledged by generous funding support by the UK Research and Innovation (UKRI) agency through the Future Fellow Fellowship, the matching funding by Cambridge University, and the support of the Isaac Newton Trust.

My research interests

Searches for New Physics: Dark Matter and Dark Sectors, long-lived Dark Sector particles, anomalous Higgs boson couplings, flavour universality violation, supersymmetry.
Precision measurements: fundamental parameters and symmetries in the Standard Model, e.g.: top quark mass, Higgs boson properties.
Detectors: development, commissioning and operation of detectors and chiefly the ANUBIS detector; reconstruction algorithms (jets, jet substructure, track-assisted jets, muons, tracks).

Coordination

Currently, I represent ANUBIS in the Physics Beyond Colliders effort and ATLAS in the LHC Dark Matter Working Group. In 2018-20, I co-lead the Common Dark Matter group, which coordinates Dark Matter searches within the ATLAS Collaboration. Previously, I lead the top quark mass group at the ATLAS Collaboration and the muon identification and track reconstruction group at the DØ Collaboration. In the context of the ATLAS and DØ Collaborations, I co-lead several analysis teams, and reviewed a two-digit number of scientific results, as an Editorial Board member or as a spokesperson sign-off delegate.

Publications

Key publications:

Key publications

ATLAS Collaboration, Search for Dark Matter Produced in Association with a Dark Higgs Boson Decaying into W±W∓ or ZZ in Fully Hadronic Final States from √s = 13 TeV pp Collisions Recorded with the ATLAS Detector, Phys. Rev. Lett. 126 (2021), 121802.
ATLAS Collaboration, Combination and summary of ATLAS dark matter searches using 139 fb−1 of √s=13 TeV pp collision data and interpreted in a two-Higgs-doublet model with a pseudoscalar mediator, ATLAS-CONF-2021-036.
M. Bauer, O. Brandt, L. Lee, C. Ohm, ANUBIS: AN Underground Belayed In-Shaft search experiment, 1919.13022.
ATLAS Collaboration, Combination of searches for invisible Higgs boson decays with the ATLAS experiment, Phys. Rev. Lett. 122, 231801 (2019).
ATLAS Collaboration, Constraints on mediator-based dark matter and scalar dark energy models using √s=13 TeV pp collision data collected by the ATLAS detector, JHEP 1905 (2019) 142.
L. Henkelmann, O. Brandt et al., LHC Dark Matter Working Group: Next-generation spin-0 dark matter models, Phys. Dark Univ. 100351.
ATLAS Collaboration, Track assisted techniques for jet substructure, ATL-PHYS-PUB-2018-012.
ATLAS Collaboration, Search for dark matter in events with a hadronically decaying vector boson and missing transverse momentum in pp collisions at √s = 13 TeV with the ATLAS detector, JHEP 10 (2018) 180.
ATLAS Collaboration, Search for pair production of Higgs bosons in the b ̄bb ̄b final state using proton-proton collisions at √s = 13 TeV with the ATLAS detector, JHEP 01 (2019) 030.
ATLAS Collaboration, Search for Dark Matter Produced in Association with a Higgs Boson Decaying to b ̄b using 36 fb−1 of pp collisions at √s = 13 TeV with the ATLAS Detector, Phys. Rev. Lett. 119, 181804, (2017).
ATLAS Collaboration, Jet mass reconstruction with the ATLAS Detector in early Run 2 data, ATLAS-CONF-2016-035 (2016).
ATLAS Collaboration, Measurement of the tt ̄ production cross-section using eμ events with b-tagged jets in pp collisions at s = 7 and 8 TeV with the ATLAS detector, Eur. Phys. J. C74 (2014) 3109.
DØ Collaboration, Muon reconstruction and identification with the Run II DØ detector, Nucl. Instrum. Meth. A 737, 281 (2014).
DØ Collaboration, Precision measurement of the top quark mass in lepton+jets final states, Phys. Rev. Lett. 113, 032002 (2014), and Phys. Rev. D 91, 112003 (2015).
DØ Collaboration, Direct measurement of the mass difference between top and antitop quarks, Phys. Rev. D 84, 052005 (2011).
ATLAS Collaboration, The ATLAS Inner Detector commissioning and calibration, Eur. Phys. J. C 70 787 (2010).
E. Abat et al., Combined performance tests before installation of the ATLAS semiconductor and transition radiation tracking detectors, JINST 3, P08003 (2008).
ATLAS Collaboration, Expected performance of the ATLAS experiment - detector, trigger and physics, arXiv:0901.0512.

Reviews

S. Argyropoulos, O. Brandt, U. Haisch, Collider Searches for Dark Matter through the Higgs Lens, Symmetry (2021) 13.
E. E. Boos, O. Brandt, D. Denisov, S. P. Denisov, P. D. Grannis, The top quark (20 years after its discovery), Phys. Usp. 58 (2015) 1133.

Other publications:

Teaching and Supervisions

Teaching:

My main teaching activity is the Part Ib Electromagnetism course. This exciting course not only represents one of the central formative pillars of the Physics Tripos (see syllabus), but also provides many opportunities for easy and didactical experimental demonstrations (>30). In addition, I teach graduate level lectures, offer Part III / MSc research projects, and carry out assessment and examination duties. Previously, I taught a wide range of courses from Electrodynamics and Atomic and Quantum Physics at undergraduate level to Statistical Methods and Particle Physics at graduate level.